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Questions related from P.K. Karmakar
Dear Colleagues, I would like to request various observational evidences about the existence of diverse (nucleus) acoustic waves in the interiors of compact astrophysical objects, such as white...
18 August 2023 3,394 0 View
It is extensively long-familiar that all-rounding pandemic disruptions transform offline synchronous (face-to-face, real) classrooms into online asynchronous (screen-to-screen, virtual) ones. It...
30 June 2021 999 46 View
The existence of turbulence in astrophysical fluids has been living as a well-known unsolved problem for a couple of decades. The range transitions among three distinct scales of the micro-fluidic...
01 June 2021 4,554 8 View
Should higher education be driven fully only by academic merit? Could it be contagious at free of cost?
06 February 2020 7,412 3 View
Academic organizations are national and international in outlook in paper. Why some people, despite higher education, have failed to get rid of regionalism and politics in eduspheres?
03 February 2020 7,737 7 View
Stars and other astrophysical structures result from the fragmentation of dust molecular clouds (DMCs). What is the relation between "Star formation rate (SFR)" and "Instability growth rate (IGR)"?
06 December 2019 4,529 0 View
Dear Colleagues, It is a fact that dust is ubiquitous almost in all the sectors of astrophysical plasma fluids. Can anyone give the quantitative values of the "dust-to-gas ratio" in varied...
17 April 2019 8,725 0 View
We are often habituated to see "dispersive waves in media" and "waves in dispersive media". So, a natural fundamental question arises in our mind. What is, or are dispersive in nature - "wave",...
26 February 2019 444 11 View
A three-dimensional (3-D, nonplanar) geometrical configuration of astrophysical fluids could be conveniently visualized. What is a justified way to visualize one-dimensional (1-D, planar)...
12 January 2019 3,252 1 View
I have a query on equation of state for astrophysical fluids. What should be a realistic and appropriate form of the equation of state to describe astrophysical fluids?
07 January 2019 5,521 3 View
The constitutive dust grains in astrophysical environments are partially ionized. What should be the most appropriate (effective) form of dust-dust interaction in astrophysical environments? In a...
30 December 2018 5,305 2 View
It is gravity, but not electric field, that matters more in astrofluids. Why is then gravity-induced electric polarization is so intense in such fluids?
30 December 2018 4,908 12 View
The Coulomb coupling parameter specifies if a plasma fluid is viscoelastic or not. In analogy with it, what is the parameter deciding whether a given neutral fluid (free from ions, radicals, or...
30 December 2018 6,674 5 View
Astrophysical fluids are gyratory and nonthermal in collective response. Is there any polytropic equation of state involving fluid rotation and nonthermal effects?
27 December 2018 756 0 View
Can any body name some astrophysical fluid instabilities still lacking theoretical explanation?
23 December 2018 1,757 1 View
Can any one suggest some classics dealing with cosmic radiations and their hydrodynamics from stability viewpoint? Interest lies both on the local as well as global behaviours of cosmic fluids.
22 December 2018 3,719 1 View
Can any body name some astrophysical objects possessing electromechanical stability properties yet to be explored?
22 December 2018 3,815 0 View
Apart from normal stability theories, there exists gas-dynamic approach as well. I have basic queries. What are the special merits of the latter? When should one apply the latter ignoring the former?
09 November 2018 4,017 0 View
Electric field is widely seen to possess only scalar potential; but, magnetic field has both scalar and vector potentials. Can anybody insightfully explain the basic physics responsible behind the...
28 October 2018 8,979 5 View
It is widely seen that large-scale cosmic fluids should be treated as "viscoelastic fluids" in theoretical formulation of their stability analyses. Can anyone explain it from the viewpoint of...
26 October 2018 383 2 View
May I get an explanation (at least possible one) on how separation of elements and crystallization of interior matter take place in course of white dwarf cooling processes? Latest study materials...
25 October 2018 3,409 0 View
I need some good reference books on electrohydrodynamic (EHD) theory of stellar winds. Could anybody help? I require it because conventionally magnetohydrodynamic (MHD) formulation is more widely...
11 September 2018 123 1 View
What are different methods useful to see nonlinear stability of plasma fluids? Which is the most accurate one?
11 August 2018 9,128 1 View
Can anyone explain physically why nonlinearity causes wave steepening and dispersion causes wave broadening effects? Demonstrations with insightful references are welcome.
01 August 2018 5,469 13 View
How do we nicely represent specific entropy conservation law in a mathematical form in diversified astrofluids?
29 July 2018 1,196 1 View
I want to get insightful helps in understanding the mechanism of peakon- or compacton-formation in plasmas. Could anyone help me out?
22 July 2018 3,304 0 View
Spherical waves are ubiquitous in astrophysical environments. Can someone provide some useful references on spherical wave analysis in spherical gravito-magnetized fluids?
22 July 2018 598 7 View
As far as seen, the usual Debye shielding mode ignores the test particle dynamics. I am interested in the usual (fluid) model of the Debye sheath for moving (non-static) object. Any suggestion...
22 July 2018 8,793 2 View
What are different types of dust grain distributions (say, in size, mass, etc) significantly applicable in astrophysical plasmas?
22 July 2018 7,137 0 View
Is there any tabular form (gallery) depicting different nonlinear equations and the corresponding eigenmodes realizable in diversified fluids? References or links are also welcome.
22 July 2018 4,468 3 View
It is well known that solitons and double layers are inter-dependent via nonlinear steepening effects arising from fluidity. Is there any explicit transformation equation from a soliton to double...
22 July 2018 3,889 0 View
I want to see a composite conjoint dispersion relation containing both "gas-acoustic" and "ion-acoustic" waves in partially ionized fluids. Both the wave features should be separable in...
08 July 2018 4,216 4 View
Electron inertial has always been usually ignored in normal plasma dynamical descriptions as far as seen. Is there any point-by-point analysis drawing a relative contrast between the plasma...
08 July 2018 8,028 2 View
A viscoelastic fluid model is allowed to undergo weakly nonlinear perturbation. There is no viscoelasticity in the lowest-order solution. What does it mean? What does it lead to?
07 July 2018 6,800 2 View
Astrofluids are characterized with the help of various thermodynamic properties and associated conservation laws. In this context, can anyone give a realistic correlation between the specific...
06 July 2018 9,940 5 View
Can two-component plasma fluids (electronic+ionic) be ever treated as a self-gravitating system in any of the real astronomical situations? Please note that a mean-fluid (MHD or EHD) approach is...
01 July 2018 3,315 10 View
I am interested in the motivated stability analysis of magnetized rotating spherical nonuniform inhomogeneous dust molecular clouds on the Jeansean scales of space-time. The components of the...
30 June 2018 4,966 1 View
The electrostatic Coulomb law has a number of demerits. Based on it, we semi-classically derive the Bohr atomic theory. Therefore, a natural question arises in fundamentality. How much is the Bohr...
26 June 2018 4,388 5 View
I have been looking for a composite dispersion relation in complex plasmas with both the "DIAW" and "DAW" features depending on the separable observation time scales for the last few weeks. The...
25 June 2018 9,416 0 View
In conventional theoretical asteroseismic investigations, the normal choice always lies in the application of plane-wave analysis despite the inherent geometrical curvature effects of the emitting...
25 June 2018 7,623 2 View
Normally, people apply plane-wave analyses even in a curved geometry, often irrespective of wavelengths. It is mostly encountered in the area of astrophysics and space sciences, even without...
23 June 2018 7,270 6 View
Gravitational instabilities are of non-local type. So, are they affected by diffusion-induced (thermo-mechanical) effects?
23 June 2018 9,784 1 View
I believe that the method of deriving the (linear) dispersion relation for any excitable mode in different plasmas with the help of normal mode analysis is well known. Why is the plasma dielectric...
20 June 2018 4,190 3 View
The conventional form of the polytropic equation of state is well known. It is based on macroscopic hydrostatic equilibrium configuration. Can anybody give me the polytropic equation of state in a...
20 June 2018 7,005 4 View
A soliton (such as, KdV soliton) has to satisfy an infinite number of conservation laws. What are the physical names and significances of such solitonic conserved properties? Please explain...
19 June 2018 5,874 2 View
What is the "Biomechanics" of "heliotropism" as exhibited by Sunflowers? Can any one technically explain the physics and chemistry responsible behind?
01 January 1970 8,910 7 View
It is well-known from the literature that there exist diverse acoustic waves in compact astrophysical objects, such as white dwarfs, neutron stars, etc. Can anyone please give us a concise glimpse...
01 January 1970 416 1 View
Can anybody suggest the most accurate laws dealing with grain mass distribution in naturalistic astrospace? Papers, books, or chapters dealing with the diversified forms of grain-mass...
01 January 1970 5,938 0 View
What are the major unsolved theoretic problems on the astrophysical dust molecular clouds and their evolutionary dynamics?
01 January 1970 9,914 1 View
Can everything (in the form of inputs plus subsequent outputs alongside other similar activities) in academics (by academicians, scientists, and researchers) be parameterized and quantified...
01 January 1970 8,361 0 View
Dear RG Members, Greetings! The dynamics of a linear Simple Harmonic Oscillator (SHO) is well studied in terms of the (a) displacement graphs, and (b) phase-space trajectories. For such a...
01 January 1970 9,202 2 View
What are the physical properties of the largest dust grain existing in astrophysical media?
01 January 1970 1,427 0 View
Can anybody suggest some physical situations of astrophysical interest to be characterized with the help of logatropic equations of state?
01 January 1970 3,145 0 View
Could anyone clearly demonstrate how rotation and turbulence exactly affect self-gravitational collapse dynamics to structure formation out of molecular clouds? Quantitative and directional...
01 January 1970 3,743 2 View
What type (polynomial, exponential, special power law, etc) of dust distribution is relevant and significant in the varied world of diversified astrophysical plasmas?
01 January 1970 1,678 1 View
